pgp - publications
Inhibition of Wnt/β-catenin signaling down-regulates P-glycoprotein and reverses multi-drug resistance of cholangiocarcinoma.
Cancer Sci. 2013 Jul 3;
Authors: Shen DY, Zhang W, Zeng X, Liu CQ
The development of multi-drug resistance (MDR) represents a major obstacle in the successful treatment of cancers. However, the factors and mechanisms lead to MDR in cholangiocarcinoma (CCA), a chemoresistant bile duct carcinoma with a poor prognosis, remain unclear. In this study, we established a human MDR CCA cell line QBC939/5-FU. Compared with QBC939 cells, more round shape, higher nuclear-cytoplasmic ratio, shorter cell cycle, faster growth, and resistant to chemotherapeutics are major characteristics of QBC939/5-FU cells. P-glycoprotein (P-gp) and β-catenin were up-regulated in QBC939/5-FU cells. Furthermore, the drug susceptibility of QBC939 cells to common chemotherapeutics was significantly decreased after Wnt3a treatment, whereas inhibition of Wnt/β-catenin pathway by β-catenin siRNA reversed the MDR of QBC939/5-FU cells to chemotherapeutics. Molecular study revealed that activation of Wnt/β-catenin pathway resulted in up-regulation of P-gp and contributed to MDR of QBC939/5-FU cells. Extraction of Siamese Crocodile 3 (ESC-3) bile enhanced the drug sensitivity of QBC939/5-FU cells to 5-FU, paralleled with down-regulation of β-catenin and P-gp. The association of Wnt/β-catenin pathway and P-gp was further confirmed by the clinical data in CCA tissues. Our study represents the first implication of Wnt/β-catenin activation in the MDR of CCA, which may be a beneficial target for the clinical treatment of CCA. This article is protected by copyright. All rights reserved.
PMID: 23822562 [PubMed - as supplied by publisher]